I was with Ooma, using an Ooma hub, before switching to an Obi 202. I didn't have any problems, but I wanted more.
Ooma is a decent choice if you want simplicity (it's easier to setup than an Obi), and can deal with the limits of the basic service or are willing to pay for the Premier service. However, I was frustrated because anytime I wanted to tweak almost anything to improve the voice quality, I had to call Ooma.
The Obi 202 is still pretty easy to setup (I don't do the automated setups), with a lot of options if needed. I do use both lines, and I like having the option of using GV plus almost any ITSP (currently, GV + Anveo + Vestalink, although I might tweak my setup in the near future). Oh, and these forums are pretty awesome.
In summary, the Obi 202 gives me more features and flexibility than an Ooma at less cost, at the cost of a more complicated (but still fairly easy) setup.